Abstract: Receive information for multiple pulse sequences are aligned as a function of phase shifts, amplitude weightings or other differences to account at least in part for inaccuracies in the transmit pulses, noise, focusing or other differences. Separate receive filters for each of the echo signals responsive to different transmit pulses provide frequency dependent amplitude weightings or phase shifts. The frequency dependent amplitude weightings or phase shifts compensate for imperfections in the transmit pulse prior to combining the echo signals. The filter may include a various number of taps or inputs, such as two or more taps, providing different spectral characteristics for different echo signals responses to the different transmit pulses. For example, N different linear receive filters are provided for echo signals responsive to each of N different transmit pulses, respectively.

Abstract: Elastography is an ultrasound imaging method, which visualizes the elastic properties of biological tissue which is often impossible with conventional ultrasound images. The tissue is hereby compressed. The local tissue strain can be visualized by comparing the ultrasound images acquired before and after compression, in order to differentiate between hard and soft tissue types. In this comparison, the time shifts of corresponding ultrasound echo signals are computed locally at one or more locations, which is time-consuming with conventional methods. The system for fast calculation of strain images from ultrasound echo signals described in this patent calculates iteratively the zero crossing of the phase of the complex HF-echo signals that are downshifted into the baseband.

Abstract: In a diagnostic ultrasound imaging system, a sequence of more than two signals is transmitted into the interrogation of the patient's body. In one embodiment of the invention, the pulses are grouped as pairs that have an inverted phase, that is, one is time-domain negative of the other. In an alternative of this embodiment, the pulses need not be paired, but rather are generated with alternating phase characteristics. The return signals are then filtered to isolate (or suppress) return signal components corresponding to portions of the interrogation region with non-linear (or linear) response characteristics. In a second embodiment of the invention, three or more pulses are generated so that have non-equidistant relative phase distribution. By combining the return signals, linear return signal components are suppressed.

Abstract: A method and apparatus are disclosed for generating a high current, high-voltage pulse suitable for driving a shock wave source of the type which generates a shock wave in an acoustic transmission medium. In the apparatus, a signal generator generates a low-voltage signal having an energy content sufficient for generating the shock wave, and a pulse-shaping network, connected between the signal generator and the shock wave source, as a transfer function which shortens the signal duration of the low voltage signal from the signal generator so that the low-voltage signal is converted into a high voltage pulse suitable for driving the shock wave source. The high-voltage pulse has an energy content substantially the same as that of the low-voltage signal.

Abstract: A catheter locatable with a non-ionizing field, such as an electromagnetic or acoustic field, has a transmitting or receiving antenna for the relevant field at its tip. Receiving or transmitting antennas for the non-ionizing field are attached to a patient in which the catheter is disposed. A receiver or transmitter is connected to these antennas, and converts the received field waves into electrical locating or image signals. The location of the catheter tip is then portrayed on a display combined with an image of the blood vessel structure acquired in a different manner, such as by x-ray imaging.

Abstract: A medical examination installation for generating images of a patient for visual display has a mechanical oscillator which vibrates at least a portion of the patient, of which an image is to be obtained, during the exposure time. The image is obtained with a pick-up device at an image frequency, and the mechanical vibration may be matched to, or differ from, the image frequency. The image is then subjected to image subtraction techniques, or selective filtering, which permits body parts which differ in terms of mechanical vibration properties from the surrounding tissue, for example calculi, to be clearly imaged, particularly the borders of those body parts.

Abstract: A medical installation for examining a patient irradiates at least a portion of the patient with an examination field, and detects the attenuated field and generates an image therefrom. During exposure of the patient to the examination field, a contrast agent injector is operated to intermittently inject contrast agent into the patient at a selected frequency. The image is generated of the patient at an image pick-up frequency, and the frequency of injection of the contrast agent may be matched to, or differ from, the image pick-up frequency. The liquid injected into the patient will have alternating sections with and without contrast agent following in succession.

Abstract: A rotating data transmission device has a rotating part, such as a rotor, and a stationary part, such as a stator. One of the parts is in the form of a waveguide coupled to a set of transmitters. The other part has a set of receivers associated therewith, the number of transmitters being different from the number of receivers. The transmitters and receivers are respectively located at positions which guarantee continuous data transmission with no interruptions during relative movement of the parts. This results during transmission in certain waveguide sections which are not always required for primary data transmission, thus making those sections available for use as secondary transmission paths. The device is particularly suited for use in a computer tomograph apparatus for transmission of measured data and control data at a high rate.